Isolated perfusion of dog kidneys will be accomplished for studies of interrelated physiology of renal hemodynamics and function. The effects of newly synthesized angiotensin polypeptides on intrarenal distribution of blood flow, the glomerular filtration rate, and salt and water excretion will be assessed. The role of dopamine and bradykinin will be mapped relative to their intrinsic activities and their abilities to release renal prostaglandins. Correlations of urine and plasma prostaglandins will be studied in basal states and after stimuli for their release. Finally tubular mechanisms for the secretion of acid will be investigated in the isolated kidney using blood made acid in vivo and in vitro. The dependency of acid formation on renal substrates and hormones will be stressed. BIBLIOGRAPHIC REFERENCES: McGiff, J.C., Itskovitz, H.D., and Terragno, N.A.: The actions of bradykinin and eledoisin in the canine isolated kidney: relationships to prostaglandins. Clin. Sci. and Mol. Med. 49: 125-131, 1975. Gotshall, R.W., and Itskovitz, H.D.: Redistribution of intrarenal blood flow by renal vasoconstriction. Fed. Proc. 34: 363, 1975.